logray

Did you put the rubber washer thing inside the cap that screws onto the reservior?

Having been bit by a cheap Laso H20 pump leaking in just 100 miles I sent it back for full credit towards the real deal.

The gauge accuracy has been covered many many times here before. But I'll entertain with a perfect example. Out today on some hard drives to get it hot and help break in my rebuilt engine while logging with Durametric. With the dash gauge just a hair right of straight up. Coolant temp was about 92-95C (197F-203F), Oil Temp about 100-105C (212F-221F). The oil temp takes longer to respond in changes than the coolant temp, and you can sorta read the oil temp from the oil pressure gauge. Gauge over the middle of the 0 in the 180, Coolant temp 100C (212F), oil temp 107-109C (224F-228F). I didn't even bother with the AC hack since it is just an extraploation of the real OBDII data. But yes, the dash temp gauge is a farse.

Having owned an EVOMS WAI, I can certainly say I miss the noise.

Just to note on step 4, the a-pillar cover simply snaps out, and does require a little force if I remember right. There are some plastic or metal compression rivets that snap the cover into place on the frame into the oval holes on the a-pillar frame in the picture above.

Since I had my bumper off recently, it was very easy to find the part number on this connector for anyone who might need it in the future. These were the marings on the connector the outdoor temp sensor plugs into: AMP 968405-1 PBTGF10

I've been thinking about adding this kit for years now. Online price was somewhere around $450 for all of the individual parts, plus shipping (and tax). Awfully tempting.

Great pictures, love the contrast. This is perhaps the best p-mera I've seen.to date. I'm still not a fan of the rear end styling. How do you feel about that part?

Aside from monitoring the post cat O2 sensors (which the DME does for you), I don't think there is much you can do. I've read you can remove them and shake them, and if they have an internal breakage and rattle significantly then that is a sign they are on their last leg, if not already gone.

Excellent, thank you again. About 50 miles on the rebuilt engine. About 20 miles since the last battery reset and parts swap. I plan to drive it heavily over the next several days, and continue monitoring. Probably at least 200 miles, but I have the first oil change coming up in about 150 miles. One interesting thing I found is the idle fuel trims keep pulling back, now at -0.07 IIRC. And the long term trims are going up a little. Over 1 now by maybe a few hundredths.

You can turn the crankshaft clockwise only and it requires a long 24mm wrench and some muscle. Play in the crankshaft pulley is from the clearance between the crankshaft and the main bearings and thrust shims. That play is measured in the thousandths of an inch. Any abnormalitites in crank play require engine tear down. In other words, I wouldn't worry about it. I think I remember a thread or two about the AC pulley, if you spend some time with search.

Thanks, I really appreciate the additional data. After 3 people chiming in I think the IATS temp might be a red herring. Here's the steps I took this morning. Disconected battery. Pulled apart IACV, completely spotless inside and out, reassembled and reconnected. Re-inspected NEW ground and power wiring, all is spotless and perfect. Reinstalled old MAF. Unplugged and disconnected unncessary all electrical loads. Tested and inspected wiring between MAF and DME and DME to DME. I could find no kinks or breaks in the lines and looked over all of the MAF wires, except I didn't unwrap the tape once it gets past the inner duct/wire mold. By feel and sight though, the tape looks undisturbed. Continuity was perfect between these wires. DME MAF pin 17 pin 5 HFM signal pin 45 pin 3 HFM ground pin 15 pin 1 IAT signal pin 47 pin 4 5V HFM Tested resistance between these wires DME MAF pin 17 pin 5 HFM signal .3 ohms pin 15 pin 1 IAT signal .3 ohms DME DME pin 17 pin 6 HFM signal to ground. Read infinity, no short to ground pin 17 pin 45 HFM signal to HFM ground. Read infinity, no short to ground pin 15 pin 6 IAT signal to HFM ground. Read infinity, no short to ground pin 15 pin 45 IAT signal to HFM ground. Read infinity, no short to ground MAF pin 1 IAT appx 5 volts pin 2 12v supply appx 12.5 volts pin 3 ground no short to ground pin 4 5v HFM appx 5 volts pin 5 HFM signal did not test Drove for appx 8 miles, until warm. On this drive the engine seems to be behaving more normal now. Power is better than it was yesterday once it's hot, and the idle seems to have really smoothed out. I am kicking myself because I didn't get very good data on the first drive I took yesterday. Yesterday it was stumbling like crazy once it got hot, especially at idle, I swear it felt like it was running lean. I already thoroughly went over all the intake to check for leaks, also used some propane, but no changes to idle. As predicted, removing the oil filler cap produces a rough idle and then very smooth again once the cap is back on and the intake leak is fixed. I went to some pretty extreme lengths to make sure there were no intake leaks during engine assembly. Also during engine assembly I meticioulsly cleaned everything inside and out, and many of the parts are new. I gathered some good data this morning, you can see at the very end the computer starts to lean out the idle range from 0.00 to -0.03 for both banks. FRA is pretty much solid on 1 or 0.99. Towards the end they seem to get better as the DME learns. At the very lowest of idle, 680 RPM there might be a very very slight mis. Hard to say though, feels much smoother now, could just be me being over sensitive. Will take it out for some more drives today and gather some more data. These numbers look much more solid to me, what do you think, especially towards the end.

:) Thanks Richard.

I PM'ed Richard to see if this was from an unmodified intake. It looks like where he lives around that time he posted his 27C IAT, the outdoor temps were similar to the past several days here (mid 50F's ish). And his temps were at idle.

No codes, just the high intake air temp reading which once the car is fully heated up (over 90C ECTS) (and the IAT is very hot) this seems to lead to rough running, seemingly late ignition timing, and perhaps leaned out fuel. I need to do more data logging though to confirm this, monitoring fuel adaption, ignition timing, and rough running values. Once the engine got hot, it stumbled a little at idle (almost like a miss, even though idle was dead on) and seems to be laboring, power seems to be down once it gets hotter. I really don't want to to be running the "new" engine in this state until I get this sorted out. When the car is started cold, and the IAT is still reading "coldish" the engine purrs, not a hint of a problem, totally smooth. It would be great to find what others typically see for an intake air temp. The only one I could find on a quick search was Richard Hamilton who observed 27C IAT at 90C engine temp, but I'm not sure if he was quoting the book, or if this was what he actually observed. I'll send him a PM to confirm this. But 27C sounds much more reasonable than the 50+ and 60+ I saw, especially on a cool day. Still though, I'm leaning towards bad wiring or I received a faulty new MAF.

Thanks Ahsai, I appreciate it. That does help to see perhaps it's not that unusual, but I would want to see moving numbers to compare with, and perhaps more numbers (bigger sampling) in general to look elsewhere for the problem. 60F outside temp today, the IAT when moving was over 30C (reached over 50 C) while driving with coolant temp over 90C (reached 100C). Later on, when it was around 55F... doing more testing... Removed MAF from housing, ignition on engine off, plugged MAF into harness, still reading 48C. Plugged in old MAF, still reading 48C. Plugged in spare DME, still reading 48C on either MAF. Makes no sense. I am thinking there might something wrong with the wiring, or I just got a bad new MAF. What seems to be happening is over time once the IAT heats up, the reading from the DME stays hot. But the mystery here is why I saw these values even after swapping the DME and MAF, even with ignition on engine off and MAF removed from the intake tube. Maybe there is a lot of resistence in the wires as they heat up, causing the wiring to be part of the equation, registering a constant voltage drop from the heat soak, which translates to a high intake temp. The good thing is I've got a ton of info and things to try tomorrow, such as bypassing wiring, measuring voltage on IAT signal wire, artificially heating/cooling the IAT, installing a fixed resistor or pot, running car without MAF, inspecting the wiring, etc. "The signal from the intake air temperature sensor is used by the DME control unit to calculate the default load signal if the mass air flow sensor fails" Based on this above info, one thing I do not know is if the IAT is used at all as part of the ignition timing or air fuel ratio if the actual MAF portion is working OK. I suppose I will find this out tomorrow if I bypass the IAT, or perhaps even unplug the MAF.

Thanks. This would explain why it starts to run like crap when the sensor starts to heats up over 30C (which did both times during first firing and the first 12 mile drive), but runs fine when it's cold. I'll take a look tomorrow at the wiring and perhaps even bypass it with direct wire runs. Maybe even hard wiring a resistor or just unplugging the MAF.

Ok doing some reading it looks like on most cars the resistance vs. temp is an inverse relationship (or negative coefficient), so as resistance increases, this incdicates lower temp, AND conversely the higher the temp, the lower the resistance. Whether this is true for the Porsche IAT in the MAF, I am not sure. But if it is like most cars, on my NEW MAF, this would mean that it is reading a lower resitance at lower temp, which should mean higher resistance. I'm really at a loss here, why with both the old and new MAF are the intake temps steadily increasing as the car warms up then once it is hot or warm the intake temp reads very hot, 120-150 degrees F. More than double what the outside air temp actually is.. Perhaps I should just hard wire a 2300 ohm resistor to the DME IAT wires and see what happens.

:( :( :( :( :( :( :( :( New MAF arrived. Ohmed pins 1 (iats) and 3 (ground) out before I installed it. At 58F it read 1700 ohms and steady. 20C is 68F. 58F is 14C. So I am "supposing" that 2300 to 2700 ohms being a normal MAF at 68F/20C correlates to a MAF reading 1700 ohms at 58F/14C. But I'm just guessing, since I haven't researched what this MAF is supposed to output, assuming that is publicly available information. So, new MAF installed and it read the correct outside/intake temperature, until about 5 miles into a 12 mile drive, it slowly started reading higher, until it reached 30C, even 48C, unfortunately after I had completed the 12 mile drive. :@ Can someone please help my sanity and put their multi meter on 2000 ohms and ohm out pins 1 and 3 on their MAF? Tell me what you get and what temp it is? I checked the MAF harness for voltage and read 5 volts on wire 1 with wire 3 being ground, which is normal. I checked the MAF harness again for voltage and read 12 volts from the supply wire and 5 volts from the MAF sensor wire, wire 3 being the ground in both cases. I checked for voltage on the ground pin and there was none. I checked for continuity between the DME harness IATS pin, MAF ground pin and the MAF harness. Continuity is perfect. I swapped the DME with my spare DME. IATS STILL reading 48C !!!! Help!

Plus, who wants bits of metal strewn about the engine or worse yet, a metal impeller grinding away at the engine case making the entire engine useless... as opposed to plastic pieces which are still dangerous but at least won't destroy your engine case if they break.

Most people try the $10 part first (you can get one at Napa). Then if that doens't work replace the entire mechanism (hundred or two). Although, if it only fails every year or two, then teh $10 part makes a whole lot more sense. :)

Overheating is much much hotter than 180-185F, or even 190F. If the engine hasn't seen higher temps than that, you aren't driving it hard enough. ;) Overheating would be water temp probably over 240 F and oil temp over 260 F ish. Spend some time with search here, there is a wealth of great info about how to read your temp gauge and also how to get the "real" temperatures from your engine, for example using a tool such as Durametric.

Yep tried cleaning it. I think it is shorted out internally. That would explain the sporradic multi meter tests and incorrect readings. I've got another MAF on order should be here tomorrow or Thursday. For now, I'm going to delay any further running of the engine since I don't want the DME think it is 145 degrees outside and lean out the AFR too much.

These are about as close as you will get for DIY, Pelican parts DIY: http://www.pelicanpa...aft_Bearing.htm Kyle's DIY (aka shark attack on rennlist): http://forums.rennlist.com/rennforums/996-forum/549133-im-going-in-alone-lne-retrofit-bearing.html

Interestingly enough, engine off of course. I installed it again and it read 19.8C. Then up to 20.3C now (which is a little high, since it's only 60F outside). Then it crept up to 21C. Now 21.8C. Bet it will keep going up if I leave the ignition on. edit, yep now 22.5C. It's only about 62F in the air box. Sounds like it's toast. Looks like there are alternatives on pelican, ebay, or amazon instead of paying $438 from a Porsche discounter.